A mass spectrometer is an apparatus for measuring and analyzing a mass of molecules. The mass spectrometer serves to ionize a sample material into ions, and to separate the generated ions in order of a mass to charge ratio. Such a mass spectrometer is composed of an ion source, a mass filter and a detector. The ion source serves to generate ions by ionizing sample gas to be analyzed, and the mass filter serves to filter ions generated from the ion source under a specific condition that only a specific mass of the ions can pass through. The detector serves to collect ions having passed the mass filter and to convert the ions into an electric signal. A result collected from the detector, which displays sample gas information, is provided to a user as an x (mass)-y (signal) plot. A mass peak can be identified using a library search program.
For an accurate identification of the sample gas, signal intensity should be high enough, and the mass filter should have a very narrow pass band. The sensitivity and mass resolution are the important factors for evaluation of the mass spectrometer performance.
In a mass spectrometer such as a gas chromatograph mass spectrometer or a residual gas analyzer, an ion source is a core component which greatly influences on sensitivity and resolution of the mass spectrometer. Accordingly, an ion source with improved ionization efficiency may be considered for higher sensitivity of the mass spectrometer.
Among the various mass spectrometers, a residual gas analyzer is widely used in the fields such as semiconductor devices, flat panel displays, industries related to vacuum and aerospace, etc.